As a result of the immense importance of the digitalization, the online world has acquired completely new dimensions. Due to the permanent pressure of competition and the rising customer demand to be permanently up-to-date, it is in the interest of every company to present their product or service online.

Apart from some important rules for an optimal web design, a company relies on the Search Engine Optimization (SEO) in order to reach the appropriate target group. This is particularly important, as regular Internet users expect search engines to lead them to content that correlates with given search terms or keywords.

Search engines, evaluate sites according to certain criteria and algorithms. They also include the so-called Rankings. These are extensive evaluation systems that are of major importance for Search Engine Optimization. In the following, we are going to reveal the relevance of the "PageRank" from Google as well as the "Alexa Rank", two of the most influential ranking lists. We will then present the comparative results of the two algorithms.

1. PageRank

The Pagerank-algorithm of Google is a special method that allows to evaluate the link popularity of a website. The aim is to prioritize the links according to their importance, in order to generate a result order when a search query is made. As a result, websites that are more popular or more important according to the number of links and the weighting factor, appear first in a search query. For Google, this method therefore provides the basis for the evaluation of websites.

The Pagerank is based on an algorithm from the fifties and has been introduced in 1998. Meanwhile, the systematics have been developed and integrated into the new Hummingbird-Algorithm in 2013. Thus, the Pagerank is still an important aspect in the calculation of the Hummingbird-algorithm, which represents one of the tools used by Google, in order to assess the popularity of a website.

Until recently, anyone was able to retrieve the PageRank through an online form. Our online-portal eBesucher also includes a Pagerank tool, that allowed to determine the PageRank of any website. However, since Google has confirmed in 2016 that PageRank values are no longer available to the public, each PageRank query results in 0/10 points. This implies a PageRank of zero.

The development history of the PageRank algorithm

The concept of link popularity had already existed, when the PageRank was developed by the computer scientists Larry Page and Sergei Brin in 1996 at the Stanford University. The aim of the implementation of the link popularity was, to protect search engines against so-called Doorway Pages. A doorway page is an intermediate page that is optimized for search engines and which leads the visitor to the main website. They are of no particular value for the user. In each link popularity concept, the value of a website increases with the number of websites that refer to it. However, many webmasters have tried to trick search engines by generating links for doorway pages from similar and automatically generated sites.

Due to the development of the PageRank, Larry Page and Sergei Brin enhanced the concept of link popularity in a way, that the link structure of the entire Internet was now integrated in the calculation: the rank of a website is no longer determined only by the number of links to this site but additionally by the relevance of these sites, the so-called Backlinks. In summary, the relevance of a website is determined recursively from the quality of those backlinks. One disadvantage of the PageRank is, that financially strong webmaster are able to achieve a higher PageRank by purchasing backlinks.

The PageRank algorithm

• PR (A) = PageRank of a site A,
• PR(Ti) = the PageRank of the sites Ti, which link to site A,
• C(Ti) = Total amount of links on site Ti and
• d = Damping Factor, whereby 0 ≤ d ≤ 1.

The PageRank of a site T is weighted by the amount C(T) of outgoing links from site T. As a consequence, the PageRank delivered from site T to site B decreases with the amount of outgoing links from site T.

2. Alexa Rank

The online service Alexa, which has been acquired by Amazon.com in 1999, primarily evaluates the quality, data traffic and links of a website. In the evaluation of page it is crucial, whether it was accessed directly or via related pages which inform about similar topics. The Alexa Rank counts and analyzes website traffic. The aim of the ranking is to determine the 1.000.000 most visited domains. Example: If your website has an Alexa Rank value of 2.000, it means that your website is amongst the 2.000 most visited sites worldwide. It is also possible to determine the ranking within certain countries.

The Alexa Toolbar

It is important to mention that Alexa only processes impressions from visitors that are using the so-called "Alexa Toolbar". The Alexa Toolbar is a plug-in that is installed in the Internet browser. It allows Alexa to evaluate the number of impressions of a website by tracking the Internet activity of each user. In order to evaluate the Alexa Rank, user data is collected over a period of 3 months. Besides the Alexa Rank, the toolbar displays related links and search requests that have led the user to the correspondent site. One disadvantage of the Alexa Toolbar is that the browser plug-in can only be installed in the following Internet browsers: "Chrome", "Firefox" and "Internet Explorer" (IE). Other web browsers such as "Opera" and "Safari" do not support the plug-in. Even though these browsers have a poor market share, the results from the Alexa Rank must be considered as selective and therefore not generally valid.
The Alexa Toolbar is free of any charge and can be found on the official website of Alexa.

Comparison: PageRank vs. Alexa Rank

PageRank

Alexa Rank

A popular indicator for the success of a website

A popular indicator for the success of a website

Is used by the most significant search engine Google and has therefore an immense reach